Valve or piston mechanism for brass band instruments



Jan. 12, 1954 c, WOHLRAB, JR

VALVE OR PISTON MECHANISM FOR BRASS BAND INSTRUMENTS Filed March 25, 1950 4 H i m I m m m WA Patented Jan. 12, 1954 VALVE OR PISTON MECHANISM FOR BRASS BAND INSTRUMENTS Curt Wohlrab, Jr., Heidelberg, Germany, assignor t Musik-Haus Wohlrab G. in. b. H., Heidelberg, Germany Application March 23, 1950, Serial No. 151,410

4 Claims.

The present invention refers generally to musical instruments and more particularly to brass band instruments. The main object of this invention is to provide an improved and modified valve or piston arrangement for such wind instruments as trumpets, trombones, cornets or the like.

In the instruments of the class referred to, the sliding branches of the main tube, which are operatively inserted into the main tube by the player to change its length and vary thereby the pitch of the tone, are placed on the outside Olf the main tube, and the valve bodies or pistons are arranged within cylinders. Such known constructions required shift lengths of from 0.75 to 1.0 inch, cannot be lubricated and are therefore hard to manipulate, or, still worse, they get accidentally stuck. They have furthermore the disadvantage that the main tube of the instrument has to be curved around the supplementary tube lengths or sliding branches and that spittle is apt to settle in pockets of the arrangement.

The present invention prevents such drawbacks by arranging the valves inside of housings and giving the valves the shape of long pistons having axial grooves of semi-circular or other cross-section which in connection with the surrounding cylinder walls form passages for the wind blown into the instrument, and so form supplementary lengths of tubing required for the purpose of lowering the pitch of the tone. To achieve relatively long passages with short pistons, the invention provides means, by which the wind entering at one end of the piston is guided towards its other end through a groove at one side of the piston, passes then through a connecting diametral hole at its extremity, and returns through a similar groove at the opposite side of the piston to the main tube. Thus the length of the branch passage is doubled and the necessary 1ength of the piston accordingly halved. For one or more supplementary tube lengths, which have to be still longer, the invention provides, instead of two axial, two helical grooves in the periphery of the piston, which also form passages in connection with the surrounding cylinder walls and are joined by a connecting diametral hole in a similar manner as the axial grooves above referred to. As a helical line is considerably longer than a straight line, a considerable increase in length of the passage is hereby achieved without increase in length of the piston. Thus, it is possible to make the sliding branches comparatively short and all of uniform length.

Another feature of the present invention resides in the fact that the main tube of the instrument to which this invention is to be applied, leads from the mouthpiece in a straight or linear line through the valve bodies and towards the bell thereby improving the tone quality resulting in simpler construction and savings in material.

The invention will now be described in connection with the accompanying drawing showing diagrammatically a, preferred embodiment thereof in connection with a trumpet, and in which:

Fig. 1 is a longitudinal section of a valve or piston mechanism according to this invention,

Fig. 2 shows the three pistons viewed perpendicularly to the plane represented in Fig. l, with the housing removed and Fig. 3 shows a partial cross-section through two pistons taken at the line A-A of Fig. 1.

Referring now to the drawing, the pistons I and 2 are slidably arranged within cylinders 3. Springs 4 maintain the pistons in their normal position in which the main tube 1 of the instrument is in alignment with corresponding ,transverse diametral openings ll through an extremity of the pistons near one end thereof. Spiral springs 4 may be arranged at either end of the pistons I and 2. The shift or stroke of the pistons amounts, in the example shown, uniformly to only 0.55 of an inch. Pistons l, inserted in two of the three cylinders 3, have two straight, axial grooves 5 of semi-circular cross-section lying diametrally opposite. Both grooves 5 are joined by a diametral connectin passage 19 at the end most remote from the main tube 7 and transverse openings In this manner the grooves 5 together with the surrounding cylinder walls and the connecting passage i8 form a passage providing a supplementary length or branch of the main tube "I. To accommodate longer tube branches on pistons of the same length, the longest branch has to amount to 10.5 inches in a trumpet for example, the two grooves of semicircular cross-section are carried around the piston in a double helix. Piston 2 is provided with such a pair of helical grooves which also are joined by a connecting diametral opening iii to complete the passage. It will be noted that thus a considerably longer tube branch is accommodated around a piston of the same length.

To retain the pistons in their proper radial position, they are provided with short keyways 6 engaged by pins (not indicated on the drawing) secured in the cylinder walls. As may be clearly seen in Fig. l the bore of the main tube '1 of the instrument passes straight through the Valve body parts 8 of pistons i and 2 said bore being thereby in alignment with the transverse diametral openings i i in said piston parts 8, when the latter are in their normal position. The pistons i and 2 may be of any material, such as metal, ebonite, Bakelite, imitation material, Plexiglas or the like.

When playing the instrument, the keys 9 are selectively depressed causing the corresponding piston to shift within its cylindrical housing. Thus the natural window, provided by the diametral opening it in the bodyportion of the piston, is closed and th passage through the groove along the piston opened, resulting in a supplementary length of tube added to the total length or tube and in a correspondingly modified pitch of tone of the instrument. When the finger is removes from the key, th piston, seated on spring instantly regains its normal position disengaging the supplementary length of tube and restoring the natural window for the wind passage.

Having thus described a preferred embodiment of the invention, it is to be understood that various modifications and arrangements of parts are possible and covered in the appending claims as being within the spirit and scope of this invention.

What I claim is:

l. A musical instrument comprising a tube, said tube having a main wind passage, at least one branch for said main wind passage, said branch comprising a housing transversely diuposed in said tube, a piston slidably disposed in said housing, said piston having formed therein a transverse wind passage adjacent one end, said transverse Wind passage being adapted to be aligned with said main Wind passage in one position of said piston, said piston further having formed therein a longitudinal wind passage, said longitudinal wind passage extending from points adjacent said transverse passage on opposite sides of said piston toward theend thereof most remote from said transverse passage, said piston further having formed therethrough a connecting passage for said longitudinally passages, said connecting passage being adjacent the end of the piston most remote from said transverse passage, said longitudinal passage further interconnecting said main passage When said transverse passage is moved out of alignment with said main passage.

2. A musical instrument comprising a linear tube having a main wind passage, a plurality of branches for said main passage, each branch comprising a cylindrical housing transversely disposed in said main tube, a piston slidably disposed in each housing, each piston having a transverse wind passage formed therethrough adjacent one end, said transverse passage being adapted to be aligned with said main passage in the normal position of said piston, each piston further having formed therein two longitudinal wind passages, the ends of-said longitudinal passages being spaced from said transverse passage and extending toward the end of said piston most remote from said transverse passage on opposite sides of said piston, each piston further having formed therethrough adjacent said most remote end a connecting passage for said longitudinal passages, said longitudinal passages being adapted to interconnect said main passage when said piston is displaced from said normal position.

3. A musical instrument comprising a linear tube with a main wind passage, at least one branch for said main passage, said branch comprising a cylindrical housing transversely disposed in said linear tube, a piston slidably disposed in said housing, said piston having a transverse Wind passage formed therethrough adjacent one end, means for aligning said transverse passage with said main passage in the normal position of said piston, the piston further having formed therein two axial grooves of semi-circular cross section forming with said housing two longitudinal wind passages on opposite sides of said cylinder, said longitudinal passages extending from points adjacent said transverse passage toward the end of said cylinder most remote from saidtransverse passage, said piston further having formed therein adjacent said most remote end a connecting passage for said longitudinal passages, said longitudinal passages further being adapted toengage said main passage when said piston is displaced from said normal position.

i. A musical instrument comprising a linear tube with a main wind passage or" circular cross section, at least one branch for said main passage, said branch comprising a cylindrical housing transversely disposed in said tube and protruding from opposite sides thereof, said housing having an internal diameter substantially equal to the diameter of said main passage, a spiral spring disposed in one end of said housing, a piston slidably disposed in said housing against the spiral spring, said piston having formed therethrough adjacent one end a transverse wind passage, said transverse wind passage having a diameter substantially equal to that of the main passage andbeing substantially aligned with said main passage in the normal position of spring, the piston further having formed therein an axial groove in the form of a helix on opposite sides thereof, said grooves extending from points adjacent said transverse passage toward the end of said piston most remote from said transverse passage, said piston further having formed therein a connecting passage for said grooves adjacent said most remote end, said grooves being adapted to engage said main passage when said piston is displaced against saidspring.

CURT WOHLRAB, JR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 935,626 Lockhart Sept. 28, 1909 1,729,568 Couturier Sept. 24, 1929 

